We have a manufacturing customer that has a current key phone system that when a page is not active, plays background music through each phone. Users can disable the background music via button on their phone. The overhead paging is separate, amplified and has an AM/FM receiver (which provides the radio station). Has anyone done this or know of a patch that can be applied to achieve this.
That would be reasoanbly easier if the background music was played by PA system, as a simple mixer with auto input selection could be used.
However, to play from phones speakers requires use of a custom application (requirin a server and based on phone SDK), so that it does not appears easy and certainly not doable with the standard product features.